NCERT Solutions For Class 6 Social Science Geography Chapter 3 - Motions of the Earth | Motion of the Earth. yash singhal edu tech world.

VERY SHORT QUESTIONS ANSWER :-

Q1. When Christmas is celebrated in Australia?

Ans. Christmas is celebrated in Australia in the summer season.

Q2. Which motion of the earth causes change in seasons?

Ans. Revolution of the earth causes change in seasons.

Q3. What is the shape of the Earth?

Ans. Earth is spherical in shape.

Q4. How long does it take the earth to complete one rotation around its axis?

Ans. The earth takes about 24 hours to complete one rotation around its axis.

Q5. When do the sun rays fall directly on the equator?

Ans. On 21^st March and September 23^rd, direct rays of the sun fall on the equator.

Q6. Why areas near the poles receive less heat?

Ans. The areas near the poles receive less heat as the rays of the sun are slanting.

Q7. What causes change in seasons?

Ans. Seasons change due to the change in the position of the earth around the sun.

Q8. Why do seasons occur?

Ans. The seasons are caused by the tilt of the Earth's rotational axis away or toward the sun as it travels around the sun in its orbit.

Q9. What is the angle of inclination of the earth’s axis with its orbital plane?

Ans. The angle of inclination of the earth’s axis with its orbital plane is 66½°.

SHORT QUESTIONS ANSWER :

Q1. Why days and nights are not of equal length?

Ans. Days and nights are not equal length because of the inclined axis of the earth. As earth is tilted at an angle of 23.4°, days are longer in summers than in winters.

Q2. Differentiate between rotation and revolution of earth.

Ans.

Rotation	Revolution
1. Rotation is the movement of the earth on its axis.	1. Revolution is the movement of the earth around the sun in a fixed path or orbit.
2. It causes day and night.	2. It causes seasons.

Q3. Why do the poles experience about six months of day and night?

Ans. The Poles experience about six months of day and six months of night because of the tilt of the Earth on its axis. When the North Pole is tilted towards the Sun, it experiences continuous daylight for six months and when the South Pole is away from the sun, it experiences continuous darkness for six months.

Q4. What would happen if the earth did not rotate?

Ans. The portion of the earth facing the sun would always experience day, thus bringing continuous warmth to the region. The other half would remain in darkness and be freezing cold all the time. Life would not have been possible in such extreme conditions.

Q5. Explain the following terms.

A. Orbital Plane

The plane formed by the orbit is known as orbital plane.

B. Circle of illumination

The portion facing the sun experiences day while the other half away from the sun experiences night. The circle that divides the day from night on the globe is called the circle of illumination.

C. Leap year

A year with 366 days is called a leap year.

D. Equinox

On 21^st March and September 23^rd, direct rays of the sun fall on the equator. At this position, neither of the poles is tilted towards the sun; so, the whole earth experiences equal days and equal nights. This is called an equinox.

LONG QUESTIONS ANSWER :

Q1. Differentiate between Summer Solstice and Winter Solstice.

Ans.

Summer Solstice	Winter Solstice
It is the position of the Earth when the rays of the sun fall directly on the Tropic of cancer.	It is the position of the Earth when the rays of the sun fall directly on the Tropic of Capricorn.
The North pole is inclined towards the sun.	The South pole is inclined towards the sun.
As large portion of the Northern Hemisphere receives light from sun, it is summer in the Northern Hemisphere.	As larger portion of the Southern Hemisphere receives light from the sun, it is summer in the Southern Hemisphere.
During this period, nights are shorter than days in Northern Hemisphere. The longest day and shortest night at these places occur on 21^st June.	During this period in Northern hemisphere, nights are longer than days